Quick release coupling



1932- H. JC-JHNSTON ET AL 1,843,230

QUICK RELEASE COUPLING Filed Feb. 15, 1931 INVENTOIZSZ HOWAIZD MILTON JOHNSTON, Tlgfif). JOHN THOMAS BQowN.

Patented Feb. 2, 1932 NIT D STATES PATENT OFFICE HOWARD MILTON JOHNSTON AND JOHN THOMAS BROWN, or TORONTO, ONTARIO,

TCANADA, ASSIGNORS TO MASSEY-HARRIS COMPANY, LIMITED, 013 TORONTO,

I ONTARIO, onNn'nn QUICK RELEASE COUPLING Application filed February 13, 1931. Serial No. 515,612.

The invention relates to quickly releasable ball and socket couplings and particularly, though not exclusively, to pitman couplings formowing machines.

In mowing machines, for example, it is important that a quickly releasable and attachable coupling be provided between the pitman and the cutter bar. The object of the invention is to provide such a coupling which is of simple construction and operation. By means of the invention the coupling may be pened or closed instantly bya manual operation. Although quickly releasable, the improved coupling is positively held in coupling position.

, Further Objects of the invention will appear hereinafter.

' The invention consists in the construction, combination and arrangement of parts hereinafter described and more particularly pointed out in the appended claims.

' Referring now to the accompanying drawings, which illustrate, by way of example, a convenient embodiment of the invention:

Figure 1 is a plan view, partly in section, showing the improved device in closed or operative position, I

Figure 2 is a plan view showing the device in open or released position, and

Figure 3 is a side elevation.

The numeral 1 indicates the free end of the pitman of a mowing machine or similar implement, and 2 indicates the ball which is carried by or connected to the cutter bar of the machine,not shown. To one side of the pitman 1 a jaw 3 is rigidly attached and to the other side is attached a jointed jaw 4. The jaws 3 and 4 are held rigidly on the pitman by any suitable means, such as bolts or rivets 5. The aw 4 is formed in two parts hinged together as at 6, one of the parts being formed with astop such as 7, to limit the opening movement of the forward part of the aw.

Adjacent the forward ends, the jaws 3 and 4 are formed with spherical socket cavities 8 adapted to engage diametrically opposite portions of the ball 2, so as to couple the pitman 1 to the cutter bar.

A hook shaped latch 9 is pivotally mounted in a recess 10 in the jaw 3 by means of a pin 11. The latch 9 extends loosely through a slot 12 in the jaw 4, and is formed on its outer end with a lug or shoulder 13.

Rotatably mounted on the outer surface of the jaw 4 is a locking member 14 provided with a cam surface 15. The locking member 14 is formcd'with a stem 16 journalled in a hole in the jaw 4, and connected to the stem on the inside of the jaw 4 is a disc 17. The inner end of the stem 16 may be squared and fitted tightly into a square hole in the disc, or any other convenient means may be adopted to ensure that the disc 17 will rotate with the member 14 and hold the member 14 rotatable in engagement with the aw 4. w A helical spring 18 is compressed between the jaw 3 and the disc 17. The disc may be formed with a groove 19 and the jaw 3 with a similar groove to receive the end coils of the spring 18. The ends of the spring 18 are anchored to the jaw 3 and disc 17 in any convenient manner as at 20.

The locking member 14 is provided with means whereby it can be readily rotated when desired. For example a lug 21 having a hole 22 may be formed on the outer surface of the member 14.

The operative position of the device is inclicated in Figure 1. In this position the socket cavities 8 are in coupling engagement with the ball 2. The spring 18 is under torsion as well as compression, the twist of the spring being such that it tends to rotate the locking member 14 in a counterclockwise direction as viewed in Figure 3. The cam surface 15 is therefore forced under the shoulder 13- as far as possible, causing the jaw 4 to be drawn towards the jaw 3 to maintain engagement of the sockets 8 and the ball 2.

lVhen it is desired to release the part which carries the ball 2, it is merely necessary to insert a bar into the hole 22 to rotate the member 14 in a clockwise direction. This action moves the narrower portion of the cam 15 towards the shoulder 13, the cam surface being automatically maintained in contact with the shoulder by the expansion of the spring 18. The jaw 4 thus moves away from the jaw 3 to the position shown in Figure 2, in which jaws to the ball, the latter is placed between position the ball 2 can be removed from the portion of the cam 15 has been moved beyond the shoulder 13 the locking member 14 is released. The shoulder 13.now automatically prevents the member 14 from being returned by the torsion of the spring. The device is thus held in they open position shown in Figure 2 and in full'lmes in Figure 3; l

W hen it is again 'deslred to connect the the cavities '8 and the endsofth'e jaws "are pinched together with the fingers. a, Assoon as the jaw 4: has been moved away from the shoulder 13 the thin portion of the cam autoinatically enters between the jaw, 4 and the shoulder 13 and the torsion of the spring causes the locking member to rotate in a counterclockwise direction from the full line position to the dotted line position in Figure 3. The spring and cam thus instantlymove the jaw 4 back tothe operative position shown in Figure ,1. j Thus only a single operation is required to release the coupling and a single operation to close the coupling. Only one hand is required for either operation, and there are no parts to be detached which might be lost or mislaid.

The parts are few in number and are of simple and inexpensive construction, readily assembled and easily operated.

It will be understood that the foregoing description and accompanying drawings are given by .way of example only and that modilications may be made within the scope of the appended claims without departing from the invention.

Claims:

'1. A releasable coupling comprising a ball, a pair of relatively movable jaws having socket cavities to engage said'ball, a latch carried by one of said jaws, a locking member carried by the other jaw and cooperating with said latch, and a spring. constantly tending both to open said jaws and operate said locking member. A a

2. A releasable coupling comprising a ball, a pair of relatively movable jaws having socket cavities to engage said ball, means for lockingisaid jaws in engagement with said ball and resilient means constantly tending both to move the jaws relatively to each other 4 and to operate the locking means. I 3. A releasable coupling comprising a ball, a pair of relatively movable jaws having socket cavities to'engage said ball, means for locking said jaws in engagement with said ball, and resilient means constantly tending both to spread said jaws apart out of engagement with said ball and to urge the locking means into locking position.

4. A releasable coupling comprising a ball, a pair of relatively movable a'ws having socket cavitiesto engage said ball, means for with said latch to' hold the jaws in engagement with said ball, and a spring compressed between said jaws and tendingto spread themapart, said spring being under torsion and tending constantly to rotate said locking memberto locking engagement with the latch. 6. Acoupling as claimed in claim 5;wherein said locking member has a cam surface on its outer face. forengageinent with a shoulder on the latch, said member having a stem on its innerface projecting through a hole in the adjacent jaw, a disc: being rigidly mounted on the inner end ofsaid stem, and

-a spring under compression and-torsional stresses having its ends anchored respectively in-saiddisc and the remote jaw.

7 A coupling as claimed in claim 5, where in said latch automatically holds said looking member in unlocked position until. the jaws are manually moved towards each other.

8. A coupling as claimed in claim 5; wherein the locking member is provided with a perforated lug on its outer face.

In testimony whereof weafiix our signatures.

HOWARD MILTON JOHNSTON. JOHN THOMAS BROWN, 

